How to compare statistical significance between 2 odds ratios calculated by logistic command

[Tarang Parekh]

Hi,
I am trying to calculate odds ratio for diabetes based on exercise pattern

Dependent variable (diabetes): 0 :No , 1: yes
Independent variable (exercise): 0: none, 1: R; 2: RW ; 3: RWS ; 4: RWST (R: running, W: walking, S: swimming , T: trekking)
controlled for : age, race, gender, education, income, employment

Here is my code:

logistic diabetes i.exercise age race gender education income employment 

	Linearized
diabetes	Odds Ratio	Std. Err.	t	P>t	[95% Conf.	Interval]
never
R	.20983	.2740315	2.74	0.006	.142138	.236655
RW	.36915	.254335	-1.00	0.316	.3363361	.421921
RWS	.53138	1.0113	2.32	0.020	.156299	.558474
RWST	.9190	.8752752	3.57	0.000	.620794	.982926

What I want is to compared Odds ratio of RWS (OR 0.53) and RWST (OR 0.91) where the difference between both of them is significant or not.
Is there any way I can do that?



Thank you for your help.

[Marcos Almeida]

You may try something like: testparm RWS - RWST

[Tarang Parekh]

Thank you for the command, Marcos.

I tried running the code and got p value= 0.521.

I understood that there is no statistically significant difference between RWS and RWST coefficient. Can I say that RWS and RWST have a similar effect on the odds of having diabetes?? I am having a hard time interpreting the outcome.

[Marcos Almeida]

Yes. But you presented a code with 7 predictors, and the output shows only 4 predictors. What is more, it is missing the first part of the regression, the one with the number of observations, R-squared, etc.

Please re-read the FAQ. There you’ll find how share data/command/output. There is a recommendation to inform ‘exactly’ what you typed and share ‘exactly’ what Stata gave you back.